This invention relates to automotive vehicle running board constructions, and more particularly to heavy duty tubular or bent-pipe running boards or similar exterior mounted steps currently in use on various sport utility and pick-up truck type automotive vehicles.
The wide spread popularity in recent years of pick-up trucks and sport utility vehicles for both on-road and off-road use in business, recreational as well as everyday travel has popularized the xe2x80x9cruggedxe2x80x9d styling of such vehicles, as well as their accessories, from both the practical as well as aesthetic standpoint. Thus the exterior running board construction provided for such vehicles, both as original equipment and after-market accessory type products, has seen the advent of a simple large tubular support, typically in the form of a two or three inch diameter steel pipe bent-formed at its opposite axial ends for connection to the undercarriage of the vehicle. A straight run central portion of the pipe is typically positioned outboard of and below the door sill of the cab of the pick-up truck or the front and/or rear doors of a sport utility vehicle (SUV). Such pipe running boards provide both the rugged strength and structural support required for such use, and are also resistant to damage from traveling through underbrush as well as from various other types of misuse encountered in the typical service life of such vehicles. Also, since the pipe is spaced outboard of the vehicle body metal it is easy to clean off, as by a hose-down, mud clinging to the surface of the pipe and to the step carried by the pipe.
Although the use of a simple pipe in and of itself has been proposed and marketed with some success, safety considerations require that a step plate of some type be mounted on top of the pipe and provided with a ribbed, corrugated or other contoured gripping pattern on its upper face. This insures safe and secure footing by users of the running board both during entry and departure from the vehicle passenger space, as well as when riding in a standing position on the running board. Hitherto, such a pipe and step plate running board construction has been provided by mounting a step plate, made as a plastic extrusion, onto the opposed edges of an upper cut-off section of a metal support pipe. The step plate was supported along its longitudinal center line by support a support beam in the form of a piece of untreated pine wood board inserted into the metal pipe. The board rested along its bottom longitudinal edge on the bottom interior of the pipe and was dimensioned so that its upper longitudinal edge abutted the underside of the plastic extrusion step plate. However, this arrangement tended to become loose and disassembled from use and abuse under normal wear and tear conditions, as well as from swelling of the wood support from water collecting in the pipe. Thus, this prior commercial construction did not provide a fully secure mounting of the step plate on the pipe and hence could be pried off during running through heavy brush or similar extreme but not unusual conditions encountered during the off-road use of such vehicles. Accordingly, it has been previously proposed (but not produced or reduced to practice) to provide a step plate/pipe running board construction in which the wood interior brace is replaced by an injection molded plastic member spanning the length and width of the interior of the pipe beneath the slotted portion of the pipe to serve as an insert support structure for a separately manufactured step plate to be mounted thereon. However, this proposed design presented problems as to its mounting assembly into a straight pipe section in order to capture the support member within the pipe, and involved an expensive and impractical procedure for assembly. Hence, this design was abandoned as being not satisfactory at least from the standpoint of secure mounting, ruggedness and/or economy of manufacture and assembly.
Accordingly, among the objects of the present invention are to provide an improved running board construction for installation and use on automotive vehicles such as pick-up trucks, SUVs and similar type vehicles wherein the aforementioned tubular pipe-type running board is employed in combination with an improved support plate member and an improved step plate member, and wherein the latter two members may be molded each as a one-piece member from plastic materials, wherein the step plate may be mounted to the support plate as a sub-assembly without use of separate fastening members and yet securely and reliably thereafter retained as a unitary sub-assembly, and wherein the step plate/support plate sub-assembly may be easily and securely mounted on the support pipe in a rapid and reliable manner, again without the use of separate fastening members.
Another object is to provide an improved running board construction of the aforementioned character that, once mounted on the running board pipe, provides a rugged and secure mount thereto that is able to withstand abuse, damage and resist pry-off removal from striking under brush and other similar forces, that is easily cleaned, that is mass producible by conventional injection molding processes and can be made in recyclable materials that are weather and moisture resistant and able to withstand the extremes of outdoor temperature conditions from dessert to arctic temperatures, that provides a safe, rattle-free, and squeak-proof standing platform mounted on the tubular pipe support and that has a long and useful service life, that is easily repairable and that is economical in construction and reliable in operation.
In general, by way of summary description and not by way of limitation, the invention accomplishes the foregoing and other objects by providing an improved vehicle running board construction comprising the aforementioned hollow metal support pipe adapted to be secured to a vehicle exterior at first and second longitudinally opposite ends of the pipe. The elongated mid-section step portion of the pipe is adapted in vehicle-mounted orientation to extend generally parallel to and adjacent a sill of a vehicle door that provides access to a passenger or freight compartment of the vehicle. An elongate mounting opening is formed in an upwardly facing exterior surface area of the pipe mid-section as defined by first and second laterally opposite and longitudinally extending opening side edges both lying in a plane chordally intersecting an upper radial cross sectional segment of the pipe. This opening is defined at opposite longitudinal ends thereof by first and second divergently inclined end edges each extending from the opening side edges to a junction with an uppermost apex area of the upwardly facing exterior surface area of said pipe.
The running board construction also includes a support plate having a plurality of transverse trusses arranged in spaced apart relation in a longitudinally extending row and straddling said opening side edges and resting thereon for support.
The support plate also has a plurality of spacer webs individually interposed between and joined to longitudinally adjacent pairs of the trusses. Each of these webs has, at each of the longitudinally opposite ends thereof, a resilient spring finger catch oriented to underlie an associated one of the pipe opening side edges. Each finger catch has a free end resiliently engaging an interior surface of the pipe for holding said step plate against upward release from the pipe.
The running board construction further includes a step plate mounted on and covering the support plate as well as the mounting opening of the pipe. The step plate has a generally flat planar central step tread portion with an undersurface bearing upon the support plate trusses. The step plate also has first and second downwardly extending side flanges respectively extending outwardly of and downwardly past the first and second pipe opening side edges. These flanges each terminate at a free end edge that preferably resiliently engages the exterior surface of the pipe. A plurality of retaining barbs extend downwardly from the step plate undersurface into snap lock tang engagement with associated receiving slot anchor tabs provided in the trusses for holding the step plate on the support plate, and vice versa.
Preferably each support plate truss has a planar top wall extending lengthwise perpendicular to the longitudinal dimension of the pipe, the truss top walls being coplanar with one another. Each of the trusses has a pair of sidewalls, one dependent from the leading and one from the trailing edges of each truss top wall. The spacer webs preferably each comprise a planar member extending in a plane parallel to the truss top walls and spaced therebelow. The opposite forward and trailing edges of each web wall are joined to the lower edges of the mutually adjacent truss sidewalls of a mutually longitudinally adjacent pair of the trusses.
Preferably each spring finger catch comprises a V-shaped member lying in a plane perpendicular to the longitudinal axis of the pipe. Each catch has a first leg that is integrally joined at its upper end to the end edge of an associated one of the spacer web walls and extends downwardly to a vertex of the V of the spring leg catch. Each catch also has a second leg extending upwardly and outwardly at an acute angle to the first leg from a junction at such vertex with the first leg, and terminates in a free end edge that forms the free end of the spring finger catch.
Preferably the support plate trusses, spacer webs and resilient spring finger catches are all integrally joined together by being injection molded with the support plate as a one-piece part, preferably from recyclable high strength thermoplastic material such as a polycarbonate.
Likewise, preferably the step plate side flanges and step plate retaining barbs are all integrally joined together by being injection molded with the step plate as a one-piece part, again perferably from a high strength recyclable plastic material such as thermoplast polyosalene containing some synthetic rubber material.
The invention also includes a method of constructing the vehicle running board construction that includes the steps of forming a sub-assembly of the plates by assembling the step plate onto the support plate by relatively moving said plates bodily toward one another while maintaining their respective longitudinal axes generally parallel until the retaining barbs have fully snap lock engaged the truss anchor tabs. Then an assembly of the support pipe with the sub-assembly is formed by relatively moving the sub-assembly and pipe bodily toward one another with the leading and trailing ends of the sub-assembly and pipe opening aligned and while maintaining their respective longitudinal axes generally parallel until the free ends of the catch second legs have been slid past the pipe opening edges and into the interior of the pipe and the step plate side flanges resiliently engage the exterior surface of the pipe.